Noah Webster & His Words, which tells the story of the person whose name is almost certainly on the dictionary in your home right now (that dictionary is, as the book tells us, the second most popular book ever printed in English, after the Bible). I was familiar with Webster's name from the dictionaries I have in my own home, but I had no idea that his work on this dictionary was part of his effort to distinguish American English from British English and to standardize spelling in the United States, thereby uniting what had only recently been 13 disparate colonies. The book's cartoonlike figures with oversized heads and spindly limbs draw children in, as do the definitions of words used in the text interspersed throughout, in dictionary format. Not only did this book teach my daughter about the life of Noah Webster, it may very well have been her first introduction to the American Revolution. Perfect for word lovers of all ages as well as lovers of American history.
There is another picture book biography of Webster: Noah Webster: Weaver of Words. It, however, is geared toward a much older audience, as it is much wordier and more detailed.